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Abstract:

The invention relates to an extendable/retractable ladder mounted to a
boat trailer to allow access to a boat carried on the trailer. The ladder
includes a pair of first vertically oriented bars and a pair of second
bars. The vertically oriented bars have an inner cavity and a slot in one
of its sides. The second bars have an inner cavity and a slot in one of
its sides. The first end of the first bars and the second end of the
second bars are connected such that the second end of the second bars can
move along the length of the first bars between an extended position in
which the first end of the second bars is a distance away from the first
bars and a retracted position in which the first end and the second end
of the second bars are adjacent to the first bars.

Claims:

1. A ladder for mounting to a boat trailer to allow access to a boat, the
ladder comprising: a pair of first, vertically oriented bars, the bars
having a length defined between a first end and a second end, an inner
cavity passing between the first end and the second end, at least two
sides, and a slot in one of the sides extending from the first end in the
direction of the second end; a pair of second bars, the bars having a
first end and a second end, an inner cavity passing between the first end
and the second end, at least two side, and a slot in one of the sides
extending from the first end in the direction of the second end, the
first end of the first bars and the second end of the second bars being
connected such that the second end of the second bars can move along the
length of the first bars between an extended position in which the first
end of the second bars is a distance away from the first bars and a
retracted position in which the first end and the second end of the
second bars are adjacent to the first bars; and a pair of third bars
pivotally connected at a first end to the second end of the first bars
and pivotally connected at a second end to the first end of the second
bars such that the second end of the third bars are at a distance away
from the first bars in an extended position and are adjacent to the first
bars in a retracted position.

2. The ladder of claim 1, wherein each of the first bars and each of the
second bars are connected using a wheel having an axel wherein each wheel
is positioned within the cavity of the first bar, the axel passes through
the slot in the side of the first bar and is mounted at the second end of
the second bar, whereby the wheels roll within the cavity of the first
bar.

3. The ladder of claim 1, wherein each of the third bars is received into
the slot in the second bars when the ladder is in a retracted position.

4. The ladder of claim 3, wherein the third bars slide into the inner
cavity of the second bars such that a portion of the third bars are
surround by a portion of the second bars in which the slot is not present
such that the second bars and third bars do not pivot relative to each
other.

5. The ladder of claim 3, wherein the third bars include a slot within
the bar, the slot positioned adjacent to the second end of the bars and
passing between a first closed end and a second closed end, whereby in
the retracted position, a portion of the slot is positioned within the
cavity of the second bars.

6. The ladder of claim 1, wherein the first bars and second bars are made
of aluminum.

7. The ladder of claim 1, wherein the third bars are made of aluminum.

8. The ladder of claim 1, wherein the second bars are joined by one or
more ladder rungs.

9. A bow stop for a boat trailer comprising the ladder of claim 1.

10. The bow stop of claim 9, wherein the bow stop is mounted to a boat
trailer.

11. A boat trailer having the ladder of claim 1.

12. A trailer having the ladder of claim 1.

13. A ladder for mounting to a trailer to allow access to the trailer,
the ladder comprising: a pair of side rails, the side rails having a
length defined between an upper, first end and a lower, second end, an
inner channel passing between the first end and the second end and
defined by at least four sides having inner and outer surfaces, and a
first slot in one of the sides passing from the inner surface to the
outer surface and extending from the first end to a middle portion of the
side and a second slot in one of the side passing from the inner surface
to the outer surface and extending from the second end to the middle
portion of the side, wherein the first slot does not extend to the second
slot; one or more ladder rungs extending between the side rails; each
side rail further including a first pin or bolt extending from at least
one side of the channel, the side being perpendicular to the side through
which the first slot is formed; a pair of bars, each bar having a length
and a lengthwise slot at one end of the bar along a portion of the length
of the bar, the first pin passing through the slot whereby the bar can
pivot about the first pin when one end of the slot is positioned against
the pin but the bar cannot pivot about the first pin when the opposite
end of the slot is positioned against the pin, and each bar has a length
that is longer than the length of the lower, second slot whereby when the
bar is positioned within the inner channel a portion of the length of the
bar is surrounded by the four side walls of the side rail such that the
side walls limit the ability of the bar to pivot about the first pin; and
a bearing or wheel positioned within the upper, first slot and mounted to
a second pin or bolt, the bearing movable along a surface of the inner
channel, whereby the bars are configured to be pivotally mounted to first
mounting plates extending through the upper, first slots and the second
pins are configured to be mounted to second mounting plates such that
when the ladder is moved to a vertical, retracted orientation the bearing
is movable against an inside surface of the inner channel along the
length of the first slot to a position at a first end of the first slot
and the bar pivots at one end with respect to the first pins and at a
second end with respect to third pins extending from the first mounting
plates, and when the ladder is moved to an extended orientation the
bearing is movable against the inside surface of the inner channel along
the length of the first slot to a position at a second end of the first
slot and the bar pivots at one end with respect to the first pins and at
a second end with respect to the third pins extending from the first
mounting plates.

14. The ladder of claim 13, wherein the first mounting plates and the
second mounting plates are mounted to a trailer.

15. The ladder of claim 13, wherein the side rails are made of aluminum.

16. The ladder of claim 13, wherein each of the bars is received into the
second slots in the side rails when the ladder is in a retracted
position.

17. A boat trailer having the ladder of claim 13.

18. A trailer having the ladder of claim 13.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from provisional patent
application No. 61/257,831 filed on Nov. 3, 2009, and entitled Extendable
Ladder for Boat Trailer or Other Trailer to Access an Elevated Surface,
the entirety of which is incorporated herein by reference.

TECHNICAL FIELD

[0002] The field of the invention generally relates to
extendable/retractable ladders mounted to boat trailers and the like for
providing improved safety and ease when accessing the boat carried on the
trailer.

BACKGROUND

[0003] The inventor has observed that there is a need for improving the
safety and ease by which individuals access the bow of a boat mounted on
a trailer, for example, to get on the boat before the trailer and boat
backed into the water to launch the boat. Current trailers typically have
a ladder mounted near the bow stop of the trailer so that a person can
climb the ladder and access the bow of the boat. The current ladders,
however, are not completely satisfactory because they either have too
much of a vertical orientation, are flimsy or narrow, do not reach the
top surface of the bow, do not come close enough to the ground to allow
easy stepping onto the ladder, or do not includes handles for climbing up
the ladder. The prior art discloses numerous other methods of mounting
ladders to objects such as vehicles.

[0004] It also is known to use ladders on trailers. For example, U.S. Pat.
No. 7,100,740 discloses a boat trailer in which a boat trailer ladder is
secured to and movable along the trailer rails. A hook engages the ladder
to standard boat trailer rails. An A-frame ladder provides steps from
approximately the level of the trailer rails, or in alternative
embodiments from approximately ground level, up for a distance above the
trailer rails.

[0005] U.S. Pat. No. 6,932,193 discloses a boat ladder attached to a
trailer for access to a bow of a boat. The ladder has two side rails with
spaced-apart steps or rungs between the side rails, the lower portion of
one of the side rails curving a predetermined distance toward the other
side rail and then running parallel with the other side rail wherein the
lower ends of the ladder side rails fit into bases secured to a front
longitudinal member of the trailer. The bases are secured on each side of
the longitudinal member, i.e., the tongue, of the trailer, and the lower
ends of the side rails fit into cylindrical tubes attached to the sides
of the base.

[0006] U.S. Pat. No. 6,782,640 discloses a boat ladder having a rigid
I-beam support with steps pivotally attached for making the ladder
compact. The ladder is pivotally engaged with a compartment in the boat
hull for storing the ladder when not in use.

[0007] U.S. Pat. No. 6,755,146 discloses a ladder which is described as
being useful as a boat ladder. The ladder is constructed with a pair of
centrally located side-by-side elongated support members which are
movable lengthwise, to a limited degree, with respect to one another. The
ladder rungs are pivotally attached to the support members such that that
when one support member is moved lengthwise the rungs are swung to extend
outward from the support members for use as a stepping ladder and swung
inward to be in line with the support members to make the ladder compact
for storage. The ladder is pivotably engageable with a storage
compartment in a boat hull for swinging the ladder downward for use from
an opening in the compartment and upward in line with the opening for
insertion into the compartment for storage.

[0008] U.S. Pat. No. 5,896,946 discloses an access step and winch mounting
assembly for a load carrying device, such as a boat trailer. The assembly
includes a front member for mounting on a frame of the trailer, a top
member extending from the front member and a cross bar connected to the
top member. The top member mounts a winch for drawing a load, such as a
boat, onto the trailer. The cross bar mounts load-engaging members. A
step subassembly includes a stringer depending downwardly from the cross
bar and multiple rungs with arcuate configurations each extending between
the front member and the stringer member. The step subassembly is
outwardly and laterally convex.

[0009] U.S. Pat. No. 4,943,076 discloses a trailer step with footing for a
person launching or loading a boat onto a trailer. The trailer step
includes a step formed with a platform and two parallel side plates. The
side plates snugly receive the trailer tongue therebetween and extend
below the tongue. Tightening bolts through the side plates sandwiches the
tongue therebetween to rigidly mount the safety trailer step to the
trailer tongue. The platform may be centered over the tongue, or it may
be laterally offset therefrom. A non-skid plastic plate may be attached
to the platform's upper surface.

SUMMARY

[0010] In one general aspect, a ladder is configured to be mounted to a
boat trailer to allow access to a boat carried on the trailer. The ladder
includes a pair of first vertically oriented bars, a pair of second bars
and a pair of third bars. The pair of first, vertically oriented bars
have a length defined between a first end and a second end, an inner
cavity passing between the first end and the second end, at least two
sides, and a slot in one of the sides extending from the first end in the
direction of the second end. The pair of second bars have a first end and
a second end, an inner cavity passing between the first end and the
second end, at least two side, and a slot in one of the sides extending
from the first end in the direction of the second end, the first end of
the first bars and the second end of the second bars being connected such
that the second end of the second bars can move along the length of the
first bars between an extended position in which the first end of the
second bars is a distance away from the first bars and a retracted
position in which the first end and the second end of the second bars are
adjacent to the first bars. The pair of third bars are pivotally
connected at a first end to the second end of the first bars and
pivotally connected at a second end to the first end of the second bars
such that the second end of the third bars are at a distance away from
the first bars in an extended position and are adjacent to the first bars
in a retracted position.

[0011] Embodiments of the ladder may include one or more of the following
features. For example, each of the first bars and each of the second bars
may be connected using a wheel having an axel wherein each wheel is
positioned within the cavity of the first bar, the axel passes through
the slot in the side of the first bar and is mounted at the second end of
the second bar, whereby the wheels roll within the cavity of the first
bar.

[0012] Each of the third bars may be received into the slot in the second
bars when the ladder is in a retracted position. The third bars may slide
into the inner cavity of the second bars such that a portion of the third
bars are surround by a portion of the second bars in which the slot is
not present such that the second bars and third bars do not pivot
relative to each other. The third bars may include a slot within the bar,
the slot positioned adjacent to the second end of the bars and passing
between a first closed end and a second closed end, whereby in the
retracted position, a portion of the slot is positioned within the cavity
of the second bars.

[0013] The first bars and second bars may be made of aluminum. The third
bars may be made of aluminum. The second bars may be joined by one or
more ladder rungs.

[0014] In another general aspect, there is provided a bow stop for a boat
trailer that includes a ladder having the features described above. The
bow stop may be mounted to a boat trailer.

[0015] In another general aspect there is provided a boat trailer having
the ladder described above with one or more of the features described
above.

[0016] In another general aspect there is provided a trailer having the
ladder described above with one or more of the features described above.

[0017] In another implementation, there is provided a ladder for mounting
to a trailer to allow access to the trailer. The ladder includes a pair
of side rails, one or more ladder rungs, and a pair of bars, and a pair
of bearings. Each side rail has a length defined between an upper, first
end and a lower, second end. The side rail has an inner channel passing
between the first end and the second end and defined by at least four
sides having inner and outer surfaces. The side rail includes a first
slot in one of the sides passing from the inner surface to the outer
surface and extending from the first end to a middle portion of the side
and a second slot in one of the side passing from the inner surface to
the outer surface and extending from the second end to the middle portion
of the side. The first slot does not extend to the second slot.

[0018] The one or more ladder rungs extend between the side rails.

[0019] Each side rail further includes a first pin or bolt extending from
at least one side of the channel, the side being perpendicular to the
side through which the first slot is formed.

[0020] Each bar has a length and a lengthwise slot at one end of the bar
along a portion of the length of the bar. The first pin passes through
the slot whereby the bar can pivot about the first pin when one end of
the slot is positioned against the pin but the bar cannot pivot about the
first pin when the opposite end of the slot is positioned against the
pin. Each bar has a length that is longer than the length of the lower,
second slot whereby when the bar is positioned within the inner channel a
portion of the length of the bar is surrounded by the four side walls of
the side rail such that the side walls limit the ability of the bar to
pivot about the first pin.

[0021] Each bearing or wheel is positioned within the upper, first slot
and mounted to a second pin or bolt, the bearing movable along a surface
of the inner channel.

[0022] The bars are configured to be pivotally mounted to first mounting
plates extending through the upper, first slots and the second pins are
configured to be mounted to second mounting plates such that when the
ladder is moved to a vertical, retracted orientation the bearing is
movable against an inside surface of the inner channel along the length
of the first slot to a position at a first end of the first slot and the
bar pivots at one end with respect to the first pins and at a second end
with respect to third pins extending from the first mounting plates.

[0023] When the ladder is moved to an extended orientation the bearing is
movable against the inside surface of the inner channel along the length
of the first slot to a position at a second end of the first slot and the
bar pivots at one end with respect to the first pins and at a second end
with respect to the third pins extending from the first mounting plates.

[0024] Embodiments of the ladder may include one or more of the features
described above or of the following. For example, the first mounting
plates and the second mounting plates may be mounted to a trailer. The
side rails may be made of aluminum.

[0025] Each of the bars may be received into the second slots in the side
rails when the ladder is in a retracted position. The ladder may be part
of a trailer or a boat trailer.

[0026] The details of various embodiments of the invention are set forth
in the accompanying drawings and the description below. Other features
and advantages of the invention will be apparent from the description,
the drawings, and the claims.

[0027] DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1 is a side view of a retractable ladder in an extended
position.

[0029] FIG. 2 is a front view of a retractable ladder in an extended
position.

[0030] FIG. 3 is a top, cross-sectional view showing a roller within the
vertically oriented bar.

[0031] FIG. 4 is a side view showing the inside view of the vertically
oriented bar.

[0032] FIG. 5 is a perspective side view of the vertically oriented bar.

[0033] FIG. 6 is a perspective side view of the angled bar.

[0034] FIG. 7 is a side view of the horizontally oriented bar.

[0035] FIG. 8 is a side view of the retractable ladder of FIG. 1 in a
partially retracted position.

[0036] FIG. 9 is a side view of the retractable ladder of FIG. 1 in a
fully retracted position.

[0037] FIG. 10 is a front view of the retractable ladder of FIG. 9 in a
fully retracted position.

[0038] FIG. 11 is a rear view of the retractable ladder of FIG. 10 taken
along section line 11 of FIG. 10.

[0039] FIG. 12 is a perspective view of the ladder of FIG. 1 mounted to a
bow stop for a boat trailer.

[0040] FIG. 13 is a perspective view of a second implementation of an
extendable ladder mounted to a trailer with the ladder being in an
extended position.

[0041] FIG. 14 is a side view of the extendable ladder of FIG. 13 showing
the ladder in the extended position.

[0042] FIG. 15 is a side view of the extendable ladder of FIG. 13 showing
the ladder in the retracted position with hidden line depictions of
components of the ladder within side rails of the ladder.

[0043] FIG. 16 is rear view of the extendable ladder of FIG. 15 showing
the ladder in the retracted position with hidden line depictions of
components of the ladder within the side rails of the ladder.

[0044] FIG. 17 is an enlarged view taken at section line 17 of FIG. 16
showing the interaction of the bar, mounting plate and pin within the
channel at the bottom of the side rail.

[0045] FIG. 18 is an enlarged view taken at section line 18 of FIG. 16
showing the interaction of the bearing, mounting plate and pin within the
channel at the top of the side rail.

[0046] FIG. 19 is an enlarged view showing the positioning of the bearing,
pin and mounting plate within the channel of the side rail.

[0047] FIG. 20 is a perspective view of a side rail of the ladder of FIG.
13 showing the slots for the bar at one end and the bearing at the other
end.

[0048] FIG. 21 is an end view of the side rail of FIG. 20.

[0049] FIG. 22 is an end view of the side rail of FIG. 20 illustrating the
position of the bearing and pin within the channel and the passage of the
mounting plate through the slot in the side rail.

DETAILED DESCRIPTION OF THE INVENTION

[0050] Referring to FIGS. 1 and 2, a ladder 100 is shown in an extended
position such that a person can climb up or down the ladder. For example,
the ladder 100 can be mounted to a boat trailer to allow a person to
climb up the ladder onto the bow of the boat. The ladder 100 can be an
integral part of the bow stop of the trailer, an integral part of the
trailer, or mounted to the bow stop as a component of the bow stop that
is mounted to the trailer.

[0051] The ladder includes a first pair of vertically oriented bars 105, a
second pair of angled bars 110, and a third pair of horizontally oriented
bars 115 that extend between the first pair of bars 105 and the second
pair of bars 110. The angled bars 110 are joined by ladder rungs 113 that
extend between the bars 110. The vertically oriented bars 105 are joined
by a pair of horizontal bars 117 that connect the vertically oriented
bars 105. The first pair of bars 105 and second pair of bars 110 are
joined at movable connections 120. The first and second bars 105, 110 can
be made of rectangular bar, for example aluminum bars. As described in
further detail below with respect to FIG. 3, the connection 120 can be in
the form of a wheel mounted to a pin in which the wheel rolls within the
rectangular bar. FIGS. 1, 4 and 5 illustrate a slot 125 formed within the
vertical bar 105. The slot 125 extends along a portion of the length of
the bar 105 between an upper opening at one end 130 of the vertical bar
105 and a lower, closed end 135 of the slot in the middle section of the
bar.

[0052] As more fully illustrated in FIG. 3, the movable connection 120
includes a wheel 140 mounted on an axle 145 extending from the wheel
through the slot 125. The wheel 140 rolls within a cavity 150 of the
vertical bar 105. The axel 145 is press fit into one or more openings in
the second bar 110. For example, if the axel is made of steel and the
second bar is made of aluminum, the axel can be easily press fit into the
opening(s). A wheel 140 is positioned in each cavity 150 of the first
bars 105 and an axel 145 is press fit into the second bar 110. In one
implementation, as illustrated in FIG. 2, the wheels 140 are on the outer
edge with the axels pointed inward. In another implementation, the wheels
are on the inner edge with the axels pointed outward. In these
configurations, the wheels 140 are able to roll within the cavities 150
with the pins passing through the slots 125. The wheels can travel
between the upper opening end 130 and the lower end 135. A pair of
handles 155 is positioned at the top of the vertical bars 105. The
handles 155 function as a handle for someone to grasp when using the
ladder as well as a stop to close the open rectangular end of the bar 105
to prevent the wheels from passing out of the bar. As also illustrated in
FIG. 2, in one implementation of the ladder the vertical bars 105 are
positioned on the outside of the bars 110.

[0053] The vertical bars 105 are also connected to the pair of
horizontally oriented bars 115 at a connection 160. The connections 160
can be formed using pins or bolts 161 that extend through one or both
walls of each vertical bar 105. One of each horizontally oriented bar 115
is positioned on each pin or bolt 161 with the pin passing through an
opening at one end of the bar. The horizontally oriented bars 115 are
solid or hollow bars, for example, made of aluminum. As illustrated in
FIG. 7, each bar 115 includes an opening 162 at one end and an enclosed
slot 164 at the other end. The pin that mounts the horizontal bar 115 to
the vertical bar 105 passes through the opening 162. The slot 164 is used
to mount the horizontal bar to the angled bar 110 at a joint 166. The
joint 166 can be formed, for example using a pin 168 press fit through
the bar 110 with the pin passing through the slot 164.

[0054] The horizontal bar 115 is oriented with respect to the vertical bar
105 and the angled bar 110 such that an upper surface 170 is oriented
upwardly and a lower surface 172 is oriented downwardly. As illustrated
in FIG. 7, the upper surface 170 includes a short cut out section 176
along a portion of its length. The lower surface 172 includes a long cut
out section 178. The cut out sections 176, 178 are sized to permit the
bar 115 to fit within the angled bar 110 through a slot 180 in a back
surface of the angled bar 110. The short cut out section 176 allows the
bar 115 to pivot within and slide into the bar 110. With the slot 164,
the bar 115 can slide up into the bar 110 and rest against a shoulder
182. The long cut out section 178 allows the bar 115 to fit completely
within the angled bar 110 when the ladder is in the retracted position.
For example, if the angled bar 110 has dimensions of 2 inches deep by 1
inches wide and the horizontal bar 115 has a 2 inch depth, the long cut
out section 178 is of a depth that is the same as the wall thickness of
the angled bar 110. It should be understood that if the horizontal bar
115 of a depth that is less than the depth of the angled bar 110 such
that the bar 115 can fit within the angled bar 110, there would be no
need for the cut out section 178.

[0055] It also should be noted from FIG. 7 that the slotted end is curved.
By curving the slotted end, the bar 115 can easily pivot within the bar
110. Upon pivoting the bar horizontal bar 115 within the angled bar 110
and sliding it up into the angled bar 110, the ladder is transitioned
from the extended position to the retracted position. In the retracted
position, a length of the bar 115 is inserted into the bar 110 beyond the
slot 180 such that the bar 115 cannot pivot with respect to the bar 110.
The bar 115 may rest against the pin 168 at one end of the slot in the
retracted position. To allow the bar 115 to pivot with respect to the bar
110, the bar 110 must be pulled up so that the pin 168 is at the opposite
end of the slot 164. The joint formed between the bars 110, 115 then can
be pushed or pulled outward from the vertical bars 105 and transitioned
into the extended position.

[0056] FIGS. 8 and 9, in combination with FIG. 1, illustrate moving the
ladder from a fully extended position (FIG. 1), to a partially
extended/retracted position (FIG. 8), to a fully retracted position (FIG.
9). In FIG. 8, the horizontal bar 115 is pivoting counterclockwise with
respect to the pins 161 and 168 while the wheel 140 is rolling upward
from a central portion of the vertical bar 105 to an upper portion of the
bar 105. In pivoting the horizontal bar 115, the bar is moved in a
direction to become coplanar with the vertical bar 105. Simultaneously,
the angled bar 110 is moved in a direction to become coplanar with both
the vertical bar 105 and the bar 115. The fully retracted position
illustrated in FIG. 9 shows the bars 105, 110, 115 in a plane. In this
position, the bar 115 is completely enclosed within the bar 110.

[0057] The fully retracted position is more completely illustrated in
FIGS. 10 and 11. FIG. 10 shows the bars 110 and rungs 113 extending
between being positioned between the vertical bars 105. The bars 115 are
positioned within the bars 110 by passing through the slots 180 machined
into the back surface of the bars 110. As illustrated in FIG. 11, because
of the slot 164 in the bar 115, the bar 115 can slide up into the bar 110
such that an end of the bar 115 extends beyond the slot 180. In this
manner, unless the bars 110 are pulled upward, the ladder 100 will be
kept fixed in a retracted position.

[0058] Referring also to FIG. 12, the ladder 100 may be part of a bow stop
200 that is part of a boat trailer or mounted to a boat trailer. The bow
stop 200 includes a bottom plate 205, a vertical post 210 extending up
from the plate 205, a pair of bow stop arms 210, and a bow stop pad 215
on each arm 210. Although many different variations are expected to work
for mounting the ladder 100 to the bow stop 200, in one implementation
the bow stop includes a mounting arm 220 to which the lower arm 117 or
vertical bars 105 are mounted. The vertical bars 105 also may be mounted
to one of the bow stop arms 210. The mounting arm 220 is coplanar with
one of the bow stop arms 210 such that the ladder 100 can be easily
mounted to the bow stop 200. Although not shown, the bow stop 200 may
include a winch mounted to the post 210 such that the winch can be used
to pull the boat up on the trailer

[0059] As is known in the art, if the bow stop 200 is a separately
manufactured part, the bow stop may be mounted to a boat trailer. To
mount the bow stop to the trailer, the plate 205 is placed on the tongue
of the trailer and then held in place, for example by bolts. One
conventional means of mounting the plate to the tongue of the trailer is
through the use of U- or C-bolts that pass over the plates and around the
trailer tongue.

[0060] Referring to FIGS. 13-22, in a second implementation, the
extendable ladder is mounted to existing mounts on a boat trailer or
other trailer. The trailer may have plates for mounting a fixed ladder to
the trailer and these plates will be used to mount the extendable ladder
to the trailer by either removing the fixed ladder or mounting to the
trailer prior to mounting of the fixed ladder. FIG. 13 shows the
extendable ladder 250 having side rails 255, 260, one or more rungs 265,
and bars 270. The bars 270 are very similar or to may be the same as the
bars 115 described above. The side rails may be made of rectangular or
square bar, such as aluminum bar or another metal material. Other durable
and strong materials may be used instead for the side rails. The ladder
permits climbing to a platform 253 on the trailer.

[0061] A hand rail, not shown, may be mounted to the platform, adjacent to
the platform or otherwise on the trailer such that an individual may
climb the extended ladder 250 to the platform while using the hand rail
for assistance. The side rails 255, 260 are mounted to plates 275 that
extend from a trailer frame. Referring also to FIG. 14, the side rails
are mounted to the plates by a bearing 280 or wheel that slides within
the side rails. Each bearing 280 is mounted to the plate 275 by means of
a pin 285 or bolt that extends from the plate and passes through the
bearing, allowing the bearing to rotate around the pin or bolt. Caps 263
positioned at the end of the side rails prevent the bearing from passing
out of the side rails when the ladder is being extended, as described in
more detail below.

[0062] The bars 270 are attached to individual side rails 255, 260 by a
pin 287 that extends through a channel 290 within each side rail from one
inside surface of the side rail to the opposite inside surface of the
side rail. The pin 287 passes through a slot 295 in the bar 270 that
extends lengthwise along a portion of the length of the bar 270. The
opposite end of the bar is mounted to a plate 297 by a pin 300 or bolt
that extends from the plate and passes through the bar. The bar can
thereby pivot with respect to the plate around the longitudinal axis of
the pin. Similarly, the bar can pivot with respect to the pin 287 passing
through the slot 295 at the other end of the bar. The bar also can slide
over the pin 287 along the slot 295 between the two ends of the slot.

[0063] FIG. 15 is a side view of the left side rail 255 using hidden lines
to show the bar 270 positioned within the channel 290 at one end of the
side rail and using hidden lines to show the bearing 280 positioned
within the channel 290. FIG. 15 differs from FIG. 14 based on the
position of the ladder. FIG. 14 illustrates the ladder 250 in an extended
position, which is evident by the bearing 280 being positioned at one end
of the side rail and the bar 270 extending from the side rail in a manner
showing the bar 270 to be being generally perpendicular to the side rail
260. In contrast, FIG. 15 shows the ladder 250 in a retracted position,
which is evident based on the bearing 280 being positioned a distance
away from the end of the side rail. This positioning indicates that the
side rail has been pushed up vertically such that one end of the side
rail is vertically positioned above the bearing. Further, in the
retracted position the entirety of the bar 270 is positioned within the
channel 290.

[0064] As illustrated in FIGS. 16 and 17, the bar 270 is of a length that
is longer than the length of a slot 305 at one end of the side rail. The
pin 287 is positioned in the channel 290 within the opening formed by the
slot 305 such that the bar can pivot around the pin. However, because the
bar has a lengthwise slot 295, the bar must be pulled vertically down
such that the pin 287 is positioned at the end of the slot to permit the
bar to pivot about the pin. If the bar is only pulled down partially, the
length of the bar on the upper side of pin will interact with one side of
the inside wall of the side rail channel and the length of the bar below
the pin will interact with the opposite side of the inside wall and
prevent a pivoting motion of the bar relative to the pin. It is this
interaction with the inside wall of the side rail channel that prevents
unintentional extension of the ladder, e.g., when the trailer is being
used to transport a boat on a road. To extend the ladder, the user must
intentionally raise the ladder up such that the end of the slot 295 is
adjacent to the pin 287. The bar then can pivot about the pin because
there is no inside wall section of the side rail to prevent the movement
of the bar relative to the pin.

[0065] FIGS. 15 and 16 also illustrate the position of the bearing 280
within the channel 290 at the top end of the ladder. FIGS. 18-22 provide
various views that show the cross section of the side rails to include an
offset slot 310 in which the plate 275 passes and the pin 285 connects to
the wheel or bearing 280. Because the slot 310 is offset from the center
of the side rail, the side wall through which the slot is formed has
sufficient land to permit the bearing to roll within the channel.

[0066] To use the extendable ladder 250 from a retracted position, the
individual grasps the side rails 255, 260 and lifts the ladder up in a
vertical direction until the individual feels the pin 287 reach the end
of the slot 295 in the bar 270. This will be evident because the ladder
cannot be lifted vertically beyond this point. While continuing to grasp
the side rails, the individual then pulls the ladder away from the
mounting plates 275, 297 on the trailer. Because the end of the slot 295
of the bar 270 is positioned at the pin 287, the side rails 255, 260 will
pivot around the pin 287 with respect to the bars 270. Simultaneously,
the interaction between the bearing 280, mounting plate 275 and the
channel 290, the top of the ladder will be pulled down while the bottom
of the ladder is pulled away from the trailer. This movement will result
in the bottom of the ladder moving down to the ground while the top of
the ladder moves down but remains approximately even with the plates 275.
The caps 263 at the top of the side rails will prevent the bearing from
sliding out of the channel and also terminate downward movement of the
ladder. Further, the pin 285 will permit the side rails to pivot with
respect to the mounting plates 275 such that the bottom of the ladder is
extended away from the trailer while the top of the ladder remains
adjacent to the trailer. The individual then can climb the rungs 265 to
reach the platform 253 and walk safely to a boat held on the trailer.
While climbing the ladder, the individual can use a handle for assistance
in climbing the ladder. Such handles may be mounted to the trailer, e.g.,
to the platform 253 or elsewhere on the trailer, and are known in the
art.

[0067] To retract the ladder, the individual grasps the side rails 255,
260 and lifts the ladder vertically while pushing the ladder in the
direction of the boat trailer. Because the ladder will pivot at the top
because of the interaction of the bearing 280, pin 285 and plate 275, the
ladder can transition to a vertical orientation. In transitioning to the
vertical orientation, the bar 270 will pivot at one end about the pin 300
to permit the bar to attain a vertical orientation. At the other end of
the bar 270, the slot 295 will slide over the pin 287 and that end of the
bar will be encompassed within the cavity 290 with the end of the bar 270
extending up into the side rail beyond the slot 305 such that at least a
portion of the bar is surrounded by all four walls of the side rail. Upon
releasing the ladder once it is in a vertical orientation, the side rails
will rest against the bars 270 and mounting plate 297. The positioning of
the top portion of the bars 270 within the channel will prevent outward
movement of the side rails and the positioning of the side rails against
the mounting plate 297 will prevent downward movement of the side rails.
In combination, these two interactions will ensure that the ladder stays
in a secure position while transporting the trailer.

[0068] While several particular forms of the invention have been
illustrated and described, it will be apparent that various modifications
and combinations of the invention detailed in the text and drawings can
be made without departing from the spirit and scope of the invention. For
example, references to materials of construction, methods of
construction, specific dimensions, shapes, utilities or applications are
also not intended to be limiting in any manner and other materials and
dimensions could be substituted and remain within the spirit and scope of
the invention. Accordingly, it is not intended that the invention be
limited, except as by the appended claims.